270 PRESENT POSITION OF 



In those industries where alcoholic fermentation is carried 

 on, the preparation of low-fermentation beers affords the 

 simplest conditions with regard to the fermentation which 

 in this case can be more easily controlled than in other 

 branches. Thus it followed, as a natural consequence, that 

 the pure culture of systematically selected species and races 

 was also first introduced in the case of this branch of 

 industry, and this again led to the introduction of appliances 

 for purifying the air, and for cooling and aerating the boiling 

 sterile wort without contact with impure air. In low-fermen- 

 tation breweries not only was pure yeast culture first carried 

 out, but the system has also attained to greater perfection in 

 this than in any other branch. The experience gained here 

 naturally afforded a basis for the experiments which were 

 made in other branches of the fermentation industry. 



The manufacture of low-fermentation beer is so nearly 

 related to that of high-fermentation beer that the application 

 of the new system to the latter branch of the industry was a 

 step which was quickly made. The slight modifications 

 which were necessary, especially with regard to the construc- 

 tion of the propagating apparatus, were carried out by Jensen, 

 Jorgensen, Kokosinski, Van Laer and Wilson. 



In the case of distilleries, pressed yeast factories, and in 

 the manufacture of wine, cider, &c., these branches of the fer- 

 mentation industry were, from their nature, the last into which 

 the new reform could gain admission. The methods employed 

 are quite different from those obtaining in low-fermentation 

 breweries ; likewise the mash and the must are usually more 

 highly infected than the wort in breweries in which even open 

 coolers are used. Nevertheless, experience shows that also 

 in the former case a vigorous pure growth of a good species 

 of yeast will, in the majority of instances, crowd out the com- 

 peting organisms present, and therefore a sufficiently pure 

 fermentation of the desired character will also, under these 

 circumstances, be obtained. As to the wine and cider, it is of 



